1. Field of the Invention
The present invention relates to a stencil discharge apparatus for removing a stencil wrapped on a stencil mounting member such as a printing cylinder of a mimeograph equipment, and adhered thereto by ink.
2. Description of the Related Art
Generally in a mimeograph equipment, an ink supply means is provided inside of a drum, and a mimeograph stencil paper can be wrapped around the outer peripheral surface of a circumferential wall which is pervious to ink. The stencil is adhered on the wall by ink. To discard a used stencil paper, generally a stencil discharge means comprising stripping pawls, a pair of discharge rollers, and a stencil receiving box is provided in the vicinity of the drum.
That is, the spent stencil paper is released, with its one end gripped by the stripping pawls in accordance with the rotation of the printing drum, from the surface of the printing drum by means of a pair of discharge rollers, and then is pushed for discharging directly into the stencil receiving box.
In FIG. 6 when a stencil paper is taken into the stencil receiving box by means of an upper roller 31 and a lower roller 32 which constitute a discharge roller pair 33, it becomes necessary to prevent the used stencil paper to be discharged from rolling back onto the discharge roller. For this purpose, in addition to the rollers of the discharge roller pair 33, a guide member comprising an upper guide plate 34 and a lower guide plate 35 is provided.
If a gap between the upper and lower guide members is set narrow, an increased load will be required to convey the used stencil paper by the discharger roller pair, giving an adverse effect to the used stencil discharging operation of the discharge roller pair. Therefore, between the upper and lower guide members there must be provided a certain degree of gap.
The discharge apparatus, however, has the following problem that where a certain degree of gap is formed between the upper and lower guide members as described above, the rear end corner portion 37 of stencil paper 36 in the vicinity of the discharge roller pair enters between the upper and lower guide members, jutting out on the entrance side of the discharge roller pair, or on the printing drum side as shown in FIG. 6. If, in this state, the stencil discharging operation is done, the leading end 38 of the stencil paper 40 that has been fed out from the printing drum is disturbed to enter into the discharge roller pair by the corner portion 37 of the preceding stencil paper 36 as shown in FIG. 7. Therefore, the entrance of both side portions 38 corresponding to the corner portions 37 of the stencil paper 40 into the discharge roller pair delays, and the whole part of the stencil paper is drawn into the rollers at center, and is discharged into the receiving box 39, resulting in an increased protruding amount of the corner portions 37 and finally in a failure in discharging the used stencil paper.
And also the discharge apparatus has the following problem that when the receiving box 39 has become full to some extent of thus discarded stencil paper, the stencil paper 40 being newly discharged will be affected by the stencil paper 36 present in the vicinity of the discharge roller pair 33, and .the corner portion 37 of the stencil paper will jut out from between the upper and lower guide plates 34 and 35 near the rollers located at both end rollers, disturbing the entrance of the corner portion 38 of the following stencil paper into the discharge rollers 33 and finally resulting in a failure in stencil discharge.
The above-described problems can be solved by providing a compressing mechanism for squeezing used stencil paper, which has been taken into the receiving box by the discharge roller pair, and a secondary operation (elevator compression or other) within the receiving box. Addition of a complicated mechanism, however, will increase the number of parts, which will present another problem such as an increase in cost.
Furthermore, the adoption of the aforementioned method will also increase the number of processes necessary for conveyance and compression of the used stencil paper discharged, increasing a possibility of occurrence of a trouble during the process.
Furthermore, it is also considered to mount the discharge roller pair in positions corresponding to the overall width of the stencil paper to be conveyed. However, the use of these discharge rollers will cause rolling the front end corners of the discharged stencil paper into a space between thee roller and the guide plate provided in other part except the rollers. That is, the front end corners of the stencil paper must be left free. The aforesaid construction, therefore, is not desirable.